You could find out when there wasn’t housing demand simply by looking house prices in an area over time. If it flattens or falls in an area, then demand has fallen. And instead of sobbing that people richer than you can afford to buy a particular house at the market rate, you should instead be lobbying state & city governments to change the absurd building codes that prevent more affordable urban housing to be built that the suburban sprawl that afflicts most US cities.
You could find out when there wasn’t housing demand simply by looking house prices in an area over time. If it flattens or falls in an area, then demand has fallen. And instead of sobbing that people richer than you can afford to buy a particular house at the market rate, you should instead be lobbying state & city governments to change the absurd building codes that prevent more affordable urban housing to be built that the suburban sprawl that afflicts most US cities.